I'm not checking this in yet -- I would like comments first.
I happened to run across the caching code in java.net.InetAddress
today. We had a couple discussions about this already in the past,
e.g. one is here:
http://gcc.gnu.org/ml/java/2000-04/msg00106.html
I still think this code is incorrect, as it doesn't respect TTL
properly. I would like to remove it, which is what this patch does.
Comments?
Tom
2006-01-11 Tom Tromey [EMAIL PROTECTED]
* java/net/InetAddress.java (DEFAULT_CACHE_SIZE): Removed.
(DEFAULT_CACHE_PERIOD, DEFAULT_CACHE_PURGE_PCT): Likewise.
(cache_size, cache_period, cache_purge_pct, cache): Likewise.
(static initializer): Removed cache code.
(checkCacheFor, addToCache): Removed.
(getAllByName): Removed cache code.
(lookup_time): Removed.
(InetAddress): Updated.
Index: java/net/InetAddress.java
===
RCS file: /cvsroot/classpath/classpath/java/net/InetAddress.java,v
retrieving revision 1.44
diff -u -r1.44 InetAddress.java
--- java/net/InetAddress.java 9 Jan 2006 18:39:22 - 1.44
+++ java/net/InetAddress.java 11 Jan 2006 21:08:17 -
@@ -43,7 +43,6 @@
import java.io.ObjectOutputStream;
import java.io.ObjectStreamException;
import java.io.Serializable;
-import java.util.HashMap;
import java.util.StringTokenizer;
/**
@@ -66,22 +65,6 @@
private static final long serialVersionUID = 3286316764910316507L;
/**
- * The default DNS hash table size,
- * Use a prime number happy with hash table.
- */
- private static final int DEFAULT_CACHE_SIZE = 89;
-
- /**
- * The default caching period in minutes.
- */
- private static final int DEFAULT_CACHE_PERIOD = 4 * 60;
-
- /**
- * Percentage of cache entries to purge when the table gets full.
- */
- private static final int DEFAULT_CACHE_PURGE_PCT = 30;
-
- /**
* The special IP address INADDR_ANY.
*/
private static InetAddress inaddr_any;
@@ -96,50 +79,8 @@
*/
static InetAddress LOCALHOST;
- /**
- * The size of the cache.
- */
- private static int cache_size = 0;
-
- /**
- * The length of time we will continue to read the address from cache
- * before forcing another lookup.
- */
- private static int cache_period = 0;
-
- /**
- * What percentage of the cache we will purge if it gets full.
- */
- private static int cache_purge_pct = 0;
-
- /**
- * HashMap to use as DNS lookup cache.
- * Use HashMap because all accesses to cache are already synchronized.
- */
- private static HashMap cache;
-
static
{
-// Look for properties that override default caching behavior
-cache_size =
- Integer.getInteger(gnu.java.net.dns_cache_size, DEFAULT_CACHE_SIZE)
- .intValue();
-cache_period =
- Integer.getInteger(gnu.java.net.dns_cache_period,
- DEFAULT_CACHE_PERIOD * 60 * 1000).intValue();
-
-cache_purge_pct =
- Integer.getInteger(gnu.java.net.dns_cache_purge_pct,
- DEFAULT_CACHE_PURGE_PCT).intValue();
-
-// Fallback to defaults if necessary
-if ((cache_purge_pct 1) || (cache_purge_pct 100))
- cache_purge_pct = DEFAULT_CACHE_PURGE_PCT;
-
-// Create the cache
-if (cache_size != 0)
- cache = new HashMap(cache_size);
-
// precompute the ANY_IF address
try
{
@@ -174,11 +115,6 @@
String hostName;
/**
- * The time this address was looked up.
- */
- transient long lookup_time;
-
- /**
* The field 'family' seems to be the AF_ value.
* FIXME: Much of the code in the other java.net classes does not make
* use of this family field. A better implementation would be to make
@@ -200,8 +136,6 @@
addr = (null == ipaddr) ? null : (byte[]) ipaddr.clone();
hostName = hostname;
-lookup_time = System.currentTimeMillis();
-
family = 2; /* AF_INET */
}
@@ -660,12 +594,6 @@
return addresses;
}
-// Check the cache for this host before doing a lookup
-addresses = checkCacheFor(hostname);
-
-if (addresses != null)
- return addresses;
-
// Not in cache, try the lookup
byte[][] iplist = VMInetAddress.getHostByName(hostname);
@@ -682,71 +610,10 @@
addresses[i] = new Inet4Address(iplist[i], hostname);
}
-addToCache(hostname, addresses);
return addresses;
}
/**
- * This method checks the DNS cache to see if we have looked this hostname
- * up before. If so, we return the cached addresses unless it has been in the
- * cache too long.
- *
- * @param hostname The hostname to check for
- *
- * @return The InetAddress for this hostname or null if not available
- */
- private static synchronized InetAddress[] checkCacheFor(String hostname)
- {
-InetAddress[] addresses = null;
-
-if (cache_size == 0)
- return null;
-
-Object obj = cache.get(hostname);
-if (obj ==
